Human error was mostly to blame for prisons wrongly opening confidential mail between inmates and their lawyers, it emerged today.

The Prisons and Probation Ombudsman investigated 32 complaints about staff opening legal and confidential access letters between April 2014 and June 2015. It upheld half of the complaints in favour of the prisoner.

The figures were published in a special bulletin ‘on the lessons that can be learned from complaints about the way prisons handled legal and confidential letters’, the independent investigatory body said.

Ombudsman Nigel Newcomen said there were ‘detailed rules’ for handling confidential mail, ‘designed to ensure that prisoners are able to communicate with their legal advisers without fear of disclosure or interference, and that they are able confidentially to communicate with independent scrutiny bodies without fear of reprisals from staff’.

Under rule 39 of the Prison Rules, inmates’ correspondence with the courts and legal advisers can be opened, stopped or read where there is reason to suspect they contain illicit items or are not from an organisation or person where rule 39 applies.

‘While I am in no way complacent, it is perhaps reassuring that, of the complaints I have upheld, most appear to be isolated incidents of human error where letters had been incorrectly opened,’ Newcomen said. ‘I found little evidence of deliberate or sinister tampering or of repeated failures at a prison.’

The prisons ombudsman said it was hard to establish exactly when an envelope was opened and by whom, but investigations begin by looking at the quality of the prison’s correspondence records, which should track rule 39 letters from arrival to reaching the prisoner. 

The ombudsman also looks for evidence of any widespread problems or deliberate tampering with privileged correspondence.

Although evidence pointed to human error rather than deliberate interference, the ombudsman said, ‘the seriousness of the breach should not be underestimated and leaves open the possibility of legal challenge’.